#define  _CRT_SECURE_NO_WARNINGS 1

#include "Stack.h"


void STInit(ST* ps)
{
	assert(ps);

	ps->a = NULL;
	ps->Capacity = 0;
	ps->top = 0;
}

void STDestory(ST* ps)
{
	assert(ps);

	free(ps->a);
	ps->a = NULL;
	ps->Capacity = ps->top = 0;
}

void STPush(ST* ps, STDataType x)
{
	assert(ps);

	if (ps->Capacity == ps->top)
	{
		int newCapacity = ps->Capacity == 0 ? 10 : (ps->Capacity + 10);
		STDataType* tmp= (STDataType*)realloc(ps->a,sizeof(ST)*newCapacity);
		if (tmp == NULL)
		{
			perror("realloc fail");
			exit(-1);
		}

		ps->a = tmp;
		ps->Capacity = newCapacity;
	}

	ps->a[ps->top] = x;
	ps->top++;
}

void STPop(ST* ps)
{
	assert(ps);
	assert(ps->top > 0);

	--ps->top;
}

STDataType STTop(ST* ps)
{
	assert(ps);
	assert(ps->top > 0);

	return ps->a[ps->top-1];
}

int STSize(ST* ps)
{
	assert(ps);

	return ps->top;
}

bool STEmpty(ST* ps)
{
	assert(ps);

	return ps->top == 0;
}